#pragma once

#include<iostream>
#include<vector>
#include<string>
#include<queue>
#include<pthread.h>
#include<unistd.h>

struct ThreadInfo
{   
    pthread_t tid;
    std::string name;
};

static const int defalutnum = 5;

template<class T>
class ThreadPool{
public:
    void Lock(){
        pthread_mutex_lock(&mutex_);
    }

    void Unlock(){
        pthread_mutex_unlock(&mutex_);
    }
    
    void Wakeup(){
        pthread_cond_signal(&cond_);
    }
    
    void ThreadSleep(){
        pthread_cond_wait(&cond_, &mutex_);
    }
    
    bool IsQueueEmpty(){
        return tasks_.empty();
    }
    
    std::string GetThreadName(pthread_t tid){
        for(const auto &ti:threads_){//线程信息
            if(ti.tid == tid){
                return ti.name;
            }
        }
        return "None";
    }
public:
    static void *HandlerTask(void *args){
        ThreadPool<T> *tp = static_cast<ThreadPool<T> *>(args);
        std::string name = tp->GetThreadName(pthread_self());
        while(true){
            tp->Lock();
            while(tp->IsQueueEmpty()){
                tp->ThreadSleep();// 解锁，等待cond
            }
            T t = tp->Pop();
            tp->Unlock();

            t();
            // std::cout<< name <<"run, "
            //         << "result: "<<t.GetResult()<<std::endl; 
        }
    }
    void Start(){
        int num = threads_.size();
        for(int i=0;i<num;i++){ 
            threads_[i].name = "thread-" + std::to_string(i);
            pthread_create(&(threads_[i].tid),nullptr,HandlerTask,this);//
        } 
    }
    T Pop(){
        T t = tasks_.front();
        tasks_.pop();
        return t;
    }
    T Push(const T &t){
        Lock();
        tasks_.push(t);
        Wakeup(); 
        Unlock();
    }
    static ThreadPool<T> *GetInstance(){
        if(nullptr == tp_){
            pthread_mutex_lock(&lock_);// 上锁
            if(nullptr == tp_){
                std::cout<< "log: singleton create done first!"<<std::endl;
                tp_ = new ThreadPool<T>();
            }
            pthread_mutex_unlock(&lock_);// 解锁
        }
        return tp_;
    }
    
private:
    ThreadPool(int num = defalutnum) :threads_(num){
        pthread_mutex_init(&mutex_,nullptr);
        pthread_cond_init(&cond_,nullptr);
    }

    ~ThreadPool(){
        pthread_mutex_destroy(&mutex_); 
        pthread_cond_destroy(&cond_);
    }
    
    ThreadPool(const ThreadPool<T>& )=delete;
    const ThreadPool<T> &operator=(const ThreadPool<T> &)=delete;

private:
    std::vector<ThreadInfo> threads_;
    std::queue<T>  tasks_;
    
    pthread_mutex_t mutex_;
    pthread_cond_t cond_;
    
    static ThreadPool<T> *tp_;
    static pthread_mutex_t lock_;
};

// 静态变量初始化
template<class T>
ThreadPool<T> * ThreadPool<T>::tp_ = nullptr;

template<class T>
pthread_mutex_t ThreadPool<T>::lock_ = PTHREAD_MUTEX_INITIALIZER;


